Structure and reactivity of [Ru(2,3-Medpp)2Cl2]2+

The structure and reactivity of the complex [Ru(2,3-Medpp)2Cl2](PF6)2 (2,3-Medpp+=2-[2-(1-methylpyridiniumyl)]-3-(2-pyridyl)pyrazine) was investigated by X-ray diffraction (XRD), 1H NMR, redox, and UV–Vis absorption measurements. X-ray analysis shows that crystals obtained from an acetonitrile–toluene solution contain the trans-Cl2, trans-pyrazine isomeric form, while 1H NMR and redox measurements on the main product of the synthetic workup indicate the presence of the trans-Cl2, cis-pyrazine isomer. In the dark at 70 °C, the complex [Ru(2,3-Medpp)2Cl2]2+ reacts slowly in acetonitrile isomerizing to the cis-[Ru(2,3-Medpp)2(CH3CN)Cl]3+ species. Under ambient light in the presence of excess AgNO3 the cis-[Ru(2,3-Medpp)2(CH3CN)2]4+ species is obtained.